Heavy metals content in water and crops in golding mining vicinity on major dams in Zamfara State, Nigeria

Abstract

The concentrations of heavy metals in water and food crops (tomatoes and cassava) grown around the three major dams in Zamfara State were gold mining are usually done were determined using standard methods. The concentration of heavy metal determined in water and food crops were generally high during the dry season with exception of Hg which recorded its highest concentration in year 2015. Zn and Cr levels in the water and food crops were within international safe limits while Cd, Pb and Hg levels were far above (0.01, 0.01 and 0.001mg/l) WHO and USEPA limits respectively. In this work, the concentration of the analyzed heavy metals in mg/l was in the order of Hg> Pb >Cd > Cr > Zn. Correlation analysis showed a significant and positive relationship for Cd and Zn and Hg and Cr during the wet season and a significant positive at the (p>0.05) relationship for Cr and Zn in the dry season. The pollution index value of the water samples across all the three dams indicated that there is need for immediate intervention to ameliorate pollution particularly in the dry season.

Keywords: Dams, Heavy metals, food crops, gold mining